+ Putting the header files into a subdirectory assumes that applications
+ will follow the (standard) practice of including the headers with
+ reference to the subdirectory name. For instance, the normal ncurses
+ header would be included using
+
+ #include <ncurses/curses.h>
+ #include <ncurses/term.h>
+
+ while the ncursesw headers would be found this way:
+
+ #include <ncursesw/curses.h>
+ #include <ncursesw/term.h>
+
+ In either case (with or without the --disable-overwrite option),
+ almost all applications are designed to include a related set of
+ curses header files from the same directory.
+
+ Manipulating the --includedir configure option to put header files
+ directly in a subdirectory of the normal include-directory defeats
+ this, and breaks builds of portable applications. Likewise, putting
+ some headers in /usr/include, and others in a subdirectory is a good
+ way to break builds.
+
+ When configured with --disable-overwrite, the installed header files'
+ embedded #include's are adjusted to use the same style of includes
+ noted above. In particular, the unctrl.h header is included from
+ curses.h, which means that a makefile which tells the compiler to
+ include directly from the subdirectory will fail to compile correctly.
+ Without some special effort, it will either fail to compile at all,
+ or the compiler may find a different unctrl.h file.
+